<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<!--poster设置封面
loop设置循环播放
muted设置为静音  autoplay自动播放(前提必须静音才能播放)
controls显示控制按钮
-->
<video poster="https://ys.mihoyo.com/main/_nuxt/img/47f71d4.jpg"
       loop autoplay
       muted controls
       style="width: 1344px; height: 756px;">
    <!--设置播放源-->
<!--
    <source src="https://ys.mihoyo.com/main/_nuxt/videos/3e78e80.mp4" type="audio/mp4">
-->
    <source src="a.mp4" type="audio/mp4">
    您的浏览器不支持播放此视频.
</video>
</body>
</html>





<script>
    /**
     *         Java:
     *              for(int i=0;i<10;i++){
     *                  int y=i+1;
     *              }
     *              int z = i+y;    //报错!  i和y超出作用域
     *
     *        JavaScript
     *              for(let i=0;i<10;i++){
     *                  let y = i+1;
     *              }
     *              let z = i+y;    //不报错, 运行时访问不到i和y 因为超出作用域
     *
     *              for(var i=0;i<10;i++){
     *                  var y = i+1;
     *              }
     *              var z = i+y;   // 不报错并且可以访问i和y变量的值
     *
     *
     *          let age = 18;
     *          let age = "abc";
     *
     *          let age;
     *
     *
     *
     *
     */



</script>




